PART 2.1: WEB API PIPELINE – Building a Scalable App Environment with Infrastructure and Deployment

Using .NET, Angular, Kubernetes, Azure/Devops, Terraform, Eventhubs and other Azure resources.

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This is one part of a series. So if you have not read the PART 0: OVERVIEW you can go there and read it to get an overview of what we will actually doing here …

Introduction

In the last PART 2: WEB API we have created our simple web api in .net core which provides a simple api for getting all messages or posting single messages. The sent messages endpoint will be sent the message to an event hub and from there it can be consumed by our workers ( which we build in the next parts!).

Now we will create a build and release pipeline (CI/CD) for our web api. The build pipeline will build the artifacts and upload the container in our azure registry.

We will create a release pipeline with two stages (acc and prd). The release pipeline will use our keyvaults and apply the secrets as environments vars to the app. We will write k8s deployment, service and ingress files to deploy the web api in our aks.

You can download the code from the git repository.

Deployment Files

Lets start with writing the needed deployment files…

Docker

Start by creating a file named “Dockerfile” in the “./.deploy” folder inside the webapi repository. Put then the following code into it.

This dockerfile is quite simple. It copies the required sources (WebApi and Common) and restore, build and publish the application. After then we define the container’s entry point. But one thing is something which could be important! I have been recognized that when I am using the default rendered dockerfile from visual studio it will not work. It is because the “runtime:3.1-buster-slim” will be used for runtime, but when running in aks it has to be the full sdk. If not then you will get an error on the aks like: “It was not possible to find any installed .NET Core SDKs”.

Kubernetes

To deploy our web api to our aks we need some deployment files. First we create a folder inside the “.deploy” folder and name it “k8s”.

We start by creating a file inside the k8s folder and name it “config.yaml”. Then put the following code into it.

We use this config file to push non secret environment variables to the application. At this time we only have one entry here for the “CORS”. Keep in mind that our web api replaces automatically values in “appsettings” with values from these environment variables.

Now we do the same with the secrets… Create a file named “secrets.yaml” besides the config.yaml. Then put the following code into it.

So here it is the same as with secrets. This variables will be pushed to the application as secrets. We have here the appinsights key, the storage connection string and the event hub connection string. All this secrets will be set inside the release pipeline later with the values from the the azure keyvault.

Now we came to the deployment file for the web api. Please create a file “deployment.yaml” and put the following code into it.

At least this deployment file pull the docker image from the azure container registry and pass our config and secret environment variables to the created pod. The values for the “ENVIRONMENT” and the “RELEASE_ARTIFACTS_BUILD_NOTIFIER_BUILDID” variables came from the release pipeline.

Then we need a k8s service, which let us connect to the application. To do that create a file and name it “service.yaml” and put the following…

We provide a service to connect to the pod over the port 8080. Now we have to provide an ingress which represents the routes for the web api in the aks. …create a file “ingress.yaml” and put the following…

This ingress will receive traffic from our public id which was created in the infrastructure part by creating the helm ingress controller. We can define here a lot, but to keep this simple, we only have one rule which routes all the traffic to our web api application on port 8080.

All this k8s files will be applied by the release pipeline, which we will see later in this post…

Build Pipeline

First we create the build pipeline and initialize terraform for our workspaces and validate them. Furthermore we create the artifact with the terraform files to later create the resources in the release pipeline.

Let’s got to azure devops now and navigate to your notifier project pipelines. The press “create pipeline” and choose Azure Repos Git for your source. Select the “Infrastructure” repository. Choose then “Starter pipeline” and click “Save and run” und yes commit it directly into the master branch. After the job has been successfully finished. Check out the repository changes from the origin. After that you should see “azure-pipelines.yml” file und your “Infrastructure” folder. From here we start to add our needed build stuff. So open the file in your editor and let’s go…

First thing to do is delete all stuff in there and then copy the following.

The trigger sets a branch where the pipeline will be automatically triggered. The repository source is to include the repositories which needed in the build. This is in our case only “self” (the repository which triggered the build). And the pool where we define our vmImage. We set it to latest ubuntu.

If we have this done, we can go to the steps. First delete all the code inside the steps section. (I have moved the pipeline file into a “.deploy” folder – if you want to do that to, you have to change the path from the yaml in the pipeline!) Lets start by setting the base configuration of the pipeline by putting the following code into the empty yaml file.

Here we set the trigger, resources, the pool and some variables. Pay attention to the resource that we include here the needed common lib repository. In the last part I describe the common lib. It is a lib which is used by web api and the workers… So it is an extra repository which you also need to create in you azure devops (if you do not have already done this!) You can download the code from the common lib here.

Now we come to the steps and tasks section… Put the following code directly under the variables section.

It begins with checking out the relevant repositories (self and common lib). In the first task we build the docker image for acc environment by our created docker file.

In the second task we push image to our container registry. The next two steps do the same for prod. You might be thinking why do we have to do the same for different environments… And yes this is only because we wanted to have every resource for every environment. But yes it is also a good idea to share some resources like the container registry. But the other has the advantage that we have real independent resources for every stage…

The next task is to copy our k8s files to the artifacts directory, so it can be uploaded in the last step as an artifact.

When you push your next changes in master branch the pipeline will be automatically triggered and should be run successfully.

Release Pipeline

For this release pipeline an hopefully already configured Azure ARM Service Connection is needed. We used this already in PART 1.1 Infrastructure Pipeline. I will here not go so much in detail of how creating the stages, adding artifacts and adding pre deployment conditions. (How to do this in detail is described in PART 1.1 Infrastructure Pipeline and can be easily adopted.)

Now let’s go to azure devops and create a release pipeline (azuredevops -> pipelines -> releases -> new) and name it “WebApi Release”. Then go to the pipeline in edit mode and start first by adding the web api artifact. At the end we want to have two stages (“acc” and “prd”). Set pre deployment conditions from “acc” to “After Release” and from “prd” to “After Stage -> acc”

Before we adding release tasks we go to the “Variables” tab and set some pipeline variables.

NameValueScope
DOMAIN_URL_BASE_NAMEnotifier.comRelease
DOMAIN_URL_SUFFIX-accacc
DOMAIN_URL_SUFFIX-prdprd
ENVIRONMENTaccacc
ENVIRONMENTprdprd
RELEASE_ARTIFACTS_BUILD_NOTIFIER_BUILDID$(Build.BuildId)Release
ApplicationInsights__InstrumentationKey$(ApplicationInsights–InstrumentationKey)Release
EventHubSettings__ConnectionString$(EventHubSettings–ConnectionString)Release
StorageSettings__ConnectionString$(StorageSettings–ConnectionString)Release

The values for app insights, event hubs and connection string comes from our key vault, which we provide through a task in the next step.

Now we start adding tasks for the release. Please go to the “Tasks” tab and select the “acc” stage. And start adding the first task “Azure Key Vault”. Set ARM Service connection and select the web api key vault. This tasks makes it possible to use the azure key vault inside the pipeline. The real cool thing here is that we have no password here it is all hidden in the key vault and the key vault access is via the service connection.

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The second task is for replacing the variables in our kubernetes deployment files by the ones from our release pipeline. We choose here the “Replace Tokens” task. Set here the kubernetes folder as root directory. The default values for a replacement match is “startwith=#{” and “endswith=}#”. So we can leave it by default because

The last task is for deploying our web api app to aks! For this we need a further service connection. So go to “Project Settings” and select “Service Connections”. Then click create new service connection from type “Kubernetes” and select your azure subscription and wait for the login window. After then you should see your clusters. Select the acc cluster and give it a name “AKS Notifier ACC”. When you have done this you can go back to your pipeline release tasks and add the last task “Kubectl”.

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Set here the Kubernetes Service Connection (in my case AKS Notifier – but in your case AKS Notifier ACC – because we have for every stage a k8s cluster). Then select the “apply” command set the path where the kubernetes deployment files are.

Then you should add the same tasks for the “prd” stage which I will not repeat here…

Verify

So ok if we now release the web api and the pipeline runs successfully then we could check if everything is working. To do that please make first a connection to the acc aks…

az aks get-credentials --resource-group notifier-resource-group-acc --name notifier-aks-acc

and then get the current services…

kubectl get services

You should now see the ingress controller which was created by infrastructure. This one should have an external ip. Then you should also see the webapi service connection running on port 8080.

Then you could check the pods…

kubectl get pods

When the pod is running, then all is good. I f you get an image loop backoff then please run the following command to get more information.

kubectl describe pod POD_NAME

I could guess that in our case it could be that the aks has no authorization to the container registry. When this is then please allow it by typing the following and create a new release.

az aks update -n notifier-aks-acc -g notifier-resource-group-acc --attach-acr notifiercontainerregistryacc

If all work up to here please call the ping (GET) endpoint (which does not uses other resouces like event hubs or something else).

GET http://YOUR_PUBLIC_IP/api/notifications/ping

If you get back “PING” then your ingress routing to your web api is working. Then go a step further lets try to get all notifications.

GET http://YOUR_PUBLIC_IP/api/notifications

When you get now an empty array. We are sure that our connection to our azurestorage is working. If this is not working then probably your connection string is wrong or was not set/replaced correctly in the pipeline.

And by posting to the endpoint a message should be sent to event hubs and the message should be saved in the azure table.

POST http://localhost:8080/api/notifications?message=hello this is my message

Conclusion

We created here a CI/CD pipeline for our web api, which is now running on an aks. The web api can be reached from outside the cluster and can be used for getting and sending notifications.

Preview

In the next chapter we are going to create the Notifier Workers (app insights, email) which can consume our notifications sent from the web api over the event hub.

PART 1: INFRASTRUCTURE – Building a Scalable App Environment with Infrastructure and Deployment

Using .NET, Angular, Kubernetes, Azure/Devops, Terraform, Eventhubs and other Azure resources.

This is one part of a serie. So if you have not read the PART 0: OVERVIEW you can go there and read it to get an overview of what we will actually doing here …

Introduction

Welcome to the first part! Now we are doing our first steps to build our notifier web application. Here we learn how to create our needed infrastructure in azure with the help of terraform. In this part we only uses a local backend for terraform which is not good, because then we run into problems when we working in teams or when we want to use pipelines. This we will cover in the next part, where we will create build/release pipelines for the infrastructure. We are going not to much deep in each configuration for the resources we create. There are so many things which are very important to know when working with all this. So I strongly recommend to go deeper into it by building your projects and researching for your needs.

Please keep in mind that when you run this terraform code you have to pay for the created azure resources. So the best is to delete the created resource groups after testing it!

What resources do we need?

If we go back to the overview part, then we see that we need the following:

Terraform

Use Infrastructure as Code to provision and manage any cloud, infrastructure, or service

https://www.terraform.io/

For me this means that it is possible to code the infrastructure no matter for what cloud. But this does not mean, that you can use your infrastructure code and change the cloud provider without changes. It means that terraform provides most cloud providers, but resources are obviously different. However coding the infrastructure has enormous advantages which are for me:

  • Put the infarstructure (as code) in a repo (versioned infrastructure)
  • Easily create complete new stages with same infrastructure (dev, tst, acc, prd, etc.)

Prerequisites

Terraform

First download the terraform cli for your os (I will use windows here for all samples – but this should not really matter). Then we need to access the cli from any location in our command line program. For this I will put this downloaded executable in C:\terraform and add a new entry in the path environment variable. If it is all correct then you should get the terraform help list by typing “terraform” in your bash/terminal/command line.

Azure CLI

Furhtermore we need the Azure CLI for authenticate to our azure account. I will do this easily with PowerShell command (Adminmode is required for this process!).

Invoke-WebRequest -Uri https://aka.ms/installazurecliwindows -OutFile .\AzureCLI.msi; Start-Process msiexec.exe -Wait -ArgumentList '/I AzureCLI.msi /quiet'; rm .\AzureCLI.msi

After installing the Azure CLI and please reopen your command line tool. Then type az. Then you should see commands from provided by the Azure CLI. Now it is time to authenticate to you azure account by typing:

az login

The browser opens automatically and you need to enter your credentials from your Microsoft account which are connected with the Azure portal. Now you will see your azure subscriptions in your command line.

Start creating

So now we will definitely start to create something. First lets create a git repository in our azure devops project “Notifier” and name it “Infrastructure” (how to). Clone it into a folder. In my case “C:\Repos\Notifier”.

Then we need an editor for writing our terraform code. I will use VSCode with the following terraform plugin Azure Terraform, but this does not really matter, we could use a simple editor for it.

Initial Terraform configuration

All starts with the main.tf file. (When calling “terraform plan” it will use all “.tf” files in the folder where terraform will be executed.) Here we can define some base settings, resource group, etc. So let’s go and create a main.tf file in our infrastructure root directory.

# Define the required provider by terraform.
provider "azurerm" {
  features {
  }
  version = "=2.33.0"
  skip_provider_registration = "true"
}

provider "helm" {
  version = "= 2.0.2"
  kubernetes {
    host                    = azurerm_kubernetes_cluster.aks.kube_config.0.host
    client_key              = base64decode(azurerm_kubernetes_cluster.aks.kube_config.0.client_key)
    client_certificate      = base64decode(azurerm_kubernetes_cluster.aks.kube_config.0.client_certificate)
    cluster_ca_certificate  = base64decode(azurerm_kubernetes_cluster.aks.kube_config.0.cluster_ca_certificate)
  }
}

# Defines our first resource - the resource group in which we create other resources.
resource "azurerm_resource_group" "rg" {
  name     = "rg_notifier_example"
 // The resource group name in azure.
  location = "West Europe"
}

The provider we are using is the “azurerm” to handle resources in azure. (When you set the “skip_provider_registration” to false, then you need to provide these in azure – what we will not cover here.). Second we define a provider for helm for creating nginx ingress controller. Then we define a resource group which we want to create.

Then we need one additional file “backend.tf”. Technically we could paste all the code in the main.tf file, but this is not very good arranged. So let’s create it in the same directory.

terraform {
  backend "local" {
}
}

We work in this part only with a local backend, so no more are required here at the moment. This means the terraform state will be created locally. (In the next chapter we change the local to a remote backend.)

Now we can initialize our terraform and create a resource group in azure. Now we have to trigger the initialization process by calling:

terrafrom init

Terraform will respond with a successful initialization message. Now we can “plan” our terraform script. The plan generates all terraform changes, adds and deletions. Terraform always uses the current state to determine the changes etc. This will not create any resource in azure! It is only a preview what will be changed when calling “apply”. So let’s check out the plan:

terraform plan

So you should see the resource group as an “add”. You should not see a change or destroy in the plan. Ok then it is time to really create our first resource. This will be done by “apply”. Apply also produces a plan which can be accepted. If “yes” then we will really made the change in azure. Ok then:

terraform apply

When we go to the azure portal, we should see our created resource group there! (Sometimes azure needs some time to finish the creation process, but this should not take long – no more than one minute.) With “terraform show” we can always take a look at our current state.

You should never change resources manually in the portal. If you do that your terraform state gets totally confused and you can damage a lot with this. So everything should be done with terraform.

Now we have all initialized, except the workspaces. In terraform we can create different workspaces and can so manage resources for different environments/stages. In our example we want limit us to use only two stages. This will be enough for demonstrating the use for it. Our application will have an “acceptance” and a “production” stage. So let’s create terraform workspaces for these two stages.

# Creates our acceptance workspace
terraform workspace new acc

# Creates our production workspace
terraform workspace new prd

# Show all worspaces (the star in the list marks the current workspace)
terraform workspace list
# Select a workspace which will be used inside the terraform code
terraform workspace select acc

Now we can take advantage of the workspaces in our terraform code. But first let’s create a folder named “settings” in our Infrastructure root folder. Inside the settings folder we create three files “prd.yaml”, “acc.yaml” and “common.yaml”. Then we add a line for the environment specific resource. One for “acc”…

resource_group_name: notifier-resource-group-acc

… and one for “prd”…

resource_group_name: notifier-resource-group-prd

… the common.yaml we need later to specify properties for all environments.

Then we reference the setting files in the main terraform script and merge the common and workspace specific settings to one settings. We use the “terraform.workspace” variable to load our setting file for that current selected workspace. Then we use our first setting variable for the resource group name. So we have a resource group for every environment. Here is the edited main.tf file:

# Define the required provider by terraform.
provider "azurerm" {
  features {
  }
  version = "=2.33.0"
  skip_provider_registration = "true"
}

provider "helm" {
  version = "= 2.0.2"
  kubernetes {
    host                    = azurerm_kubernetes_cluster.aks.kube_config.0.host
    client_key              = base64decode(azurerm_kubernetes_cluster.aks.kube_config.0.client_key)
    client_certificate      = base64decode(azurerm_kubernetes_cluster.aks.kube_config.0.client_certificate)
    cluster_ca_certificate  = base64decode(azurerm_kubernetes_cluster.aks.kube_config.0.cluster_ca_certificate)
  }
}

# Here we define settings which will be used when creating the resources.
locals {
  default_tfsettings = {

  }

  commonSettingsFile = "./settings/common.yaml"
  commonSettingsFileContent = fileexists(local.commonSettingsFile) ? file(local.commonSettingsFile) : "NoTFCommonSettingsFileFound: true"
  commonSettings = yamldecode(local.commonSettingsFileContent)

  workspaceSettingsFile = "./settings/${terraform.workspace}.yaml"
  workspaceSettingsFileContent = fileexists(local.workspaceSettingsFile) ? file(local.workspaceSettingsFile) : "NoTFWorkspaceSettingsFileFound: true"
  workspaceSettings = yamldecode(local.workspaceSettingsFileContent)

  settings = merge(local.default_tfsettings, local.commonSettings, local.workspaceSettings)
}

# Defines our first resource - the resource group in which we create other resources.
resource "azurerm_resource_group" "rg" {
  name     = local.settings.resource_group_name
 // The resource group name in azure.
  location = "West Europe"
}

Adding further resources

Now we have to add our resources we need for the application …

Application Insights

First we create a file named “application-insights.tf” in this we put the following code to create the resource. (Terraform will automatically detect the new .tf files.)

resource "azurerm_application_insights" "ai" {
  name                = local.settings.application_insights_name // Name of the resource defined in the settings file. 
  location            = azurerm_resource_group.rg.location // Use resource group location.
  resource_group_name = azurerm_resource_group.rg.name // Use our resource group from the current workspace.
  application_type    = "other" // The type of application. We use "other" here, so it is not so specific like "web", "java", etc.
  retention_in_days   = 90 // The default retention used here.
  sampling_percentage = 100 // To get the most accurate results without so many loose of data.
}

This is very simple right? So we define here the resource where we set the name from the settings file depend on the workspace we have selected. The location and resource group name came directly from our created resource group in the main.tf before. But we definitely need to add the application insights name in the setting files.

application_insights_name: notifier-application-insights-acc
application_insights_name: notifier-application-insights-prd

After this is all done we can call terraform plan to verify our changes und then apply to create the resource. Please make sure that you have selected the “acc” workspace. Ando not wonder when you call “plan” that the resource group resource will be added again. This is why we have applied the plan in the default workspace and not in the acc! In this part we will apply only in acc. In the next part when we create a pipeline for the infrastructure this will be done by the release!

terraform plan
terraform apply
Container Registry

Creating a container registry is also easy as with the application insights. Create a new file called “container-registry.tf” and put the following code to it. Please read the comments for more information.

resource "azurerm_container_registry" "acr" {
  name                = local.settings.application_insights_name // Name of the resource defined in the settings file. 
  location            = azurerm_resource_group.rg.location // Use resource group location.
  resource_group_name = azurerm_resource_group.rg.name // Use our resource group from the current workspace.
  sku                 = "Basic" // We will use the not so expensive one for this demo.
}

Then like always add entries for the name in the setting files. But for this resource we can only use lowercase alpha numeric values, so we can not use the “-” for separating words.

container_registry_name: notifiercontainerregistryacc # Some resources can only use alphanumeric names.
container_registry_name: notifiercontainerregistryprd # Some resources can only use alphanumeric names.

And apply our new stuff …

terraform plan
terraform apply
Kubernetes Service (AKS)

Time for adding our k8s cluster. Create a file in the “Infrastructure” root folder (like with the others) and name it “kubernetes-cluster.tf” and put the following code into it for a basic managed k8s cluster.

resource "azurerm_kubernetes_cluster" "aks" {
  name                = local.settings.aks_name
  location            = azurerm_resource_group.rg.location
  resource_group_name = azurerm_resource_group.rg.name
  dns_prefix          = local.settings.aks_dns_prefix

  default_node_pool {
    name       = "default"
    node_count = 1
    vm_size    = "Standard_A2_v2"
  }

  identity {
    type = "SystemAssigned"
  }

  tags = {
    Environment = local.settings.aks_tag_environment
  }
}

output "client_certificate" {
  value = azurerm_kubernetes_cluster.aks.kube_config.0.client_certificate
}

output "kube_config" {
  value = azurerm_kubernetes_cluster.aks.kube_config_raw
}

resource "helm_release" "ingress" {
    name      = local.settings.ingress_name
    repository = "https://charts.bitnami.com/bitnami"
    chart      = "nginx-ingress-controller"
    set {
        name  = "rbac.create"
        value = "true"
    }
}

This is a very basic config for the cluster. Please take a look at terraform to get more infos. The vm_size defined in line 10 should be minimum “Standard_A2_v2”. You need 2 CPU’s and 4 GB RAM. I took the “Standard_A” version, because it is sufficient for testing purposes and it is to that fact a little cheaper.

At least we define a helm release ingress resource. This is our ingress controller which creates a public id and make it possible to reach the aks outside of the cluster. We use two workspace dependent settings here which we have to add in our setting files.

aks_name: notifier-aks-acc
aks_dns_prefix: notifieraksacc
aks_tag_environment: Acceptance
aks_name: notifier-aks-prd
aks_dns_prefix: notifieraksprd
aks_tag_environment: Production

And again apply our new stuff … This can take some time (ca. 5 minutes). After everything worked correctly you get an output with a client certificate.

terraform plan
terraform apply
Event Hubs

For creating our event hub, we need first an event hub namespace in which our notifications event hub will be running in. For this please create a file named “eventhub-namespace.tf” and put the following code into it.

resource "azurerm_eventhub_namespace" "ehns" {
  name                      = local.settings.eventhub_namespace.name
  location                  = azurerm_resource_group.rg.location
  resource_group_name       = azurerm_resource_group.rg.name
  sku                       = "Standard"
  capacity                  = local.settings.eventhub_namespace.capacity
  auto_inflate_enabled      = true
  maximum_throughput_units  = local.settings.eventhub_namespace.maximum_throughput_units
  network_rulesets          = [{
    default_action       = "Deny"
    ip_rule              = []
    virtual_network_rule = []      
  }]

  tags = {
    "creator"     = "markus herkommer"
    "environment" = terraform.workspace
  }
}

So nothing special her … We create a namespace for each workspace and use workspace settings to apply different configurations. The “sku” must be min “Standard”, but terraform will inform you about that, if you try basic :).

Before we declare the needed settings lets create our actual event hub, because there we will need to add some more settings. Now we create a file and name it “eventhub-notification.tf” and put the following code to it.

# Define the eventhub
resource "azurerm_eventhub" "notifications" {
  name                = "notifications"
  namespace_name      = azurerm_eventhub_namespace.ehns.name
  resource_group_name = azurerm_resource_group.rg.name
  partition_count     = local.settings.eventhub.notifications.partition_count
  message_retention   = local.settings.eventhub.notifications.message_retention
}

# Define eventhub consumers
resource "azurerm_eventhub_consumer_group" "notifications_notifier_appinsights" {
  name                = "appinsights"
  namespace_name      = azurerm_eventhub_namespace.ehns.name
  eventhub_name       = azurerm_eventhub.notifications.name
  resource_group_name = azurerm_resource_group.rg.name
}

resource "azurerm_eventhub_consumer_group" "notifications_notifier_email" {
  name                = "email"
  namespace_name      = azurerm_eventhub_namespace.ehns.name
  eventhub_name       = azurerm_eventhub.notifications.name
  resource_group_name = azurerm_resource_group.rg.name
}

# Define eventhub authorization rules
resource "azurerm_eventhub_authorization_rule" "notifications_notifier_send" {
  name                = "send"
  namespace_name      = azurerm_eventhub_namespace.ehns.name
  eventhub_name       = azurerm_eventhub.notifications.name
  resource_group_name = azurerm_resource_group.rg.name
  listen              = false
  send                = true
  manage              = false
}

resource "azurerm_eventhub_authorization_rule" "notifications_notifier_listen" {
  name                = "listen"
  namespace_name      = azurerm_eventhub_namespace.ehns.name
  eventhub_name       = azurerm_eventhub.notifications.name
  resource_group_name = azurerm_resource_group.rg.name
  listen              = true
  send                = false
  manage              = false
}

In the first section we create the notifications event hub. In the next section our two needed consumers. (The two notifier workers – app insights and email). And in the last part we set authorization rules for this event hub. We set a rule for sending and receiving messages. And when we come to the end for every resource we need to add our used setting variables in the workspace files.

eventhub_namespace:
    name: eventhubs-acc
    capacity: 1
    maximum_throughput_units: 10

eventhub:
    notifications:
        partition_count: 2
        message_retention: 7
eventhub_namespace:
    name: eventhubs-prd
    capacity: 1
    maximum_throughput_units: 10

eventhub:
    notifications:
        partition_count: 4
        message_retention: 7

And I am sure you guess it what’s next to do …

terraform plan
terraform apply
Table Storage

To save the notifications we a need a storage and we want to store the data in azure table storage. For this we need a storage account resource. We could create the table in our services, or directly in terraform. For this time we will create it in the service later.

Create a file named “storage-account.tf” in the also known “Infrastructure” directory and put the following code in there:

resource "azurerm_storage_account" "sa" {
  name                     = local.settings.storage_account_name
  resource_group_name      = azurerm_resource_group.rg.name
  location                 = azurerm_resource_group.rg.location
  account_tier             = "Standard"
  account_kind             = "StorageV2"
  account_replication_type = "LRS"
}

In the first part we define the storage account and use the version 2 of the storage account here, but actually the V1 should also work. Our replication type is LRS which means, that our data will only be replicated in one region, which is totally ok for our use. The second part creates the table inside our storage account. Now we need to define the storage account names. (Here are only lowercase alphanumeric values allowed.)

storage_account_name: notifierstoreacc
storage_account_name: notifierstoreprd

and again …

terraform plan
terraform apply
Key Vaults

For getting access to our resources we need connectionstrings and passwords, etc. The best place for it are the key vaults. The key vaults can be used in pipelines and in our .net core services. We should create key vaults for each service. This does not really matter here, because the secrets are nearly the same, but we want to do it in a microservice manner and separate them. So we have access control over these entries per service.

Before we start to create the key vault configurations we need to add some common settings.

tenant_id: YOUR_TENANT_ID

kv_allow:
    notifier-devs:
        object_id: CURRENT_LOGGED_IN_USER_OBJECT_ID
        secret_permissions: ["get", "list", "delete", "set", "recover", "backup", "restore"]

Your tenant you can find by “az account list”. For your the object id from your current user (The user you are logged in with az login.) you can find in the azure portal. Azure Active Directory -> Users -> YOUR USER. This is needed for the key vault access policy. We will see very soon…

Now we need to add some workspace specific settings and add the key vault names.

keyvault_webapi_name: kv-webapi-acc
keyvault_worker_appinsights_name: kv-worker-insights-acc
keyvault_worker_email_name: kv-worker-email-acc
keyvault_webapi_name: keyvault-webapi-prd
keyvault_worker_appinsights_name: keyvault-worker-appinsights-prd
keyvault_worker_email_name: keyvault-worker-email-prd

After adding the settings we create a file named “keyvault-webapi.tf” and putting the following code to it:

# Key vault definition
resource "azurerm_key_vault" "kv_webapi" {
  name                        = local.settings.keyvault_webapi_name
  location                    = azurerm_resource_group.rg.location
  resource_group_name         = azurerm_resource_group.rg.name
  enabled_for_disk_encryption = false
  enabled_for_template_deployment = true
  tenant_id                   = local.settings.tenant_id
  soft_delete_enabled         = true
  soft_delete_retention_days  = 7
  purge_protection_enabled    = false
  sku_name = "standard"
}

# Access policy
resource "azurerm_key_vault_access_policy" "ap_webapi_admin" {
  for_each     = local.settings.kv_allow
  key_vault_id = azurerm_key_vault.kv_webapi.id

  tenant_id = local.settings.tenant_id
  object_id = each.value.object_id

  secret_permissions = each.value.secret_permissions
}

# Key vault entries
resource "azurerm_key_vault_secret" "kvs_webapi_appinsights" {
  name         = "ApplicationInsights--InstrumentationKey"
  value        = azurerm_application_insights.ai.instrumentation_key
  key_vault_id = azurerm_key_vault.kv_webapi.id
  depends_on = [azurerm_key_vault_access_policy.ap_webapi_admin]
}

resource "azurerm_key_vault_secret" "kvs_webapi_storage" {
  name         = "StorageSettings--ConnectionString"
  value        = azurerm_storage_account.sa.primary_connection_string
  key_vault_id = azurerm_key_vault.kv_webapi.id
  depends_on = [azurerm_key_vault_access_policy.ap_webapi_admin]
}

resource "azurerm_key_vault_secret" "kvs_webapi_eventhub" {
  name         = "EventHubSettings--ConnectionString"
  value        = azurerm_eventhub_authorization_rule.notifications_notifier_send.primary_connection_string
  key_vault_id = azurerm_key_vault.kv_webapi.id
  depends_on = [azurerm_key_vault_access_policy.ap_webapi_admin]
}

First we define the key vault. The second one is very important – the access policy. Here we define where has access to the key vaults. We already defined this in our common file – do you remember? And in this definition a foreach loop iterates over these settings and set access for the defined object id’s, which can be groups, users, or service connections. In the last section we create our entries for application insights, the connection string for the storage account (storage tables) and the connection string for sending messages to our notifications event hub.

Let’s go to the next key vault by creating a file named “keyvault-worker-appinsights.tf” and putting the following code to it:

# Key vault definition
resource "azurerm_key_vault" "kv_worker_appinsights" {
  name                        = local.settings.keyvault_worker_appinsights_name
  location                    = azurerm_resource_group.rg.location
  resource_group_name         = azurerm_resource_group.rg.name
  enabled_for_disk_encryption = false
  tenant_id                   = data.azurerm_client_config.cc.tenant_id
  sku_name = "standard"
}

resource "azurerm_key_vault_access_policy" "ap_worker_appinsights_admin" {
  key_vault_id = azurerm_key_vault.kv_worker_appinsights.id
  tenant_id = data.azurerm_client_config.cc.tenant_id
  object_id = data.azurerm_client_config.cc.object_id
  secret_permissions = [
    "get",
    "list",
    "set",
    "delete",
    "recover",
    "backup",
    "restore"
  ]
}

# Key vault entries
resource "azurerm_key_vault_secret" "kvs_worker_appinsights_appinsights" {
  name         = "ApplicationInsights--InstrumentationKey"
  value        = azurerm_application_insights.ai.instrumentation_key
  key_vault_id = azurerm_key_vault.kv_worker_appinsights.id
  depends_on = [azurerm_key_vault_access_policy.ap_worker_appinsights_admin]
}

resource "azurerm_key_vault_secret" "kvs_worker_appinsights_eventhub" {
  name         = "EventHubSettings--ConnectionString"
  value        = azurerm_eventhub_authorization_rule.notifications_notifier_listen.primary_connection_string
  key_vault_id = azurerm_key_vault.kv_worker_appinsights.id
  depends_on = [azurerm_key_vault_access_policy.ap_worker_appinsights_admin]
}

The definition is analog to the previous key vault. We create here an application insights and an event hub with listen connection string secret here.

Next the last one which is nearly the same except the name of the key vault. So create a file named “keyvault-worker-email.tf” and put the following code into that file:

# Key vault definition
resource "azurerm_key_vault" "kv_worker_email" {
  name                        = local.settings.keyvault_worker_email_name
  location                    = azurerm_resource_group.rg.location
  resource_group_name         = azurerm_resource_group.rg.name
  enabled_for_disk_encryption = false
  tenant_id                   = data.azurerm_client_config.cc.tenant_id
  sku_name = "standard"
}

resource "azurerm_key_vault_access_policy" "ap_worker_email_admin" {
  key_vault_id = azurerm_key_vault.kv_worker_email.id
  tenant_id = data.azurerm_client_config.cc.tenant_id
  object_id = data.azurerm_client_config.cc.object_id
  secret_permissions = [
    "get",
    "list",
    "set",
    "delete",
    "recover",
    "backup",
    "restore"
  ]
}

# Key vault entries
resource "azurerm_key_vault_secret" "kvs_worker_email_appinsights" {
  name         = "ApplicationInsights--InstrumentationKey"
  value        = azurerm_application_insights.ai.instrumentation_key
  key_vault_id = azurerm_key_vault.kv_worker_email.id
  depends_on = [azurerm_key_vault_access_policy.ap_worker_email_admin]
}

resource "azurerm_key_vault_secret" "kvs_worker_email_eventhub" {
  name         = "EventHubSettings--ConnectionString"
  value        = azurerm_eventhub_authorization_rule.notifications_notifier_listen.primary_connection_string
  key_vault_id = azurerm_key_vault.kv_worker_email.id
  depends_on = [azurerm_key_vault_access_policy.ap_worker_email_admin]
}

and for the last time in this post …

terraform plan
terraform apply

If everything had worked correctly the notifier-resource-group-acc in the azure portal should look like this.

image by author

Now you could check the event hubs and check, that we have our two consumers there and a shared access policy for “send” and “listen”. And make sure all secrets was written in the key vaults, but this should all be ok, else terraform has report us an error.

Please also notice two more resource groups which was created by helm for the ingress controller.

Conclusion

So you have “learned” how to start with terraform and create a bunch of resources which we will need for our scalable notifier web application. There are a lot of more options for every resource we have defined. Please take a look at terraform.

All that stuff we have written here is downloadable from the public repository: https://dev.azure.com/sternschleuder/Notifier/_git/Infrastructure?version=GBfeature%2Fpart1. Please let me know if you have any suggestions or questions.

Preview

In the next PART 1.1 we will create pipelines for our created infrastructure. This is very helpful. Then we do no more have to do “plan” and “apply” in our command line. It is then a part of the overall publishing process with all it’s benefits like, CI, approval process, stages, etc.

PART 0: OVERVIEW – Building a Scalable App Environment with Infrastructure and Deployment

Using .NET, Angular, Kubernetes, Azure/Devops, Terraform, Eventhubs and other Azure resources.
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image by author

This post will be he first of a series, because it makes no sense to put all that stuff into one post. So this post will outline the overall demo application and infrastructure and how we will start to develop it.

What do we learn here?

We will build a modern style web application environment which uses a lot of technologies to bring that up and running. We learn how to wire all that pieces together and automate them. Starting by creating the infrastructure in azure using terraform and integrate it with azure devops pipelines. Then we are going to create a simple webapi in .net core which uses azure tables to store data and an event hub for posting messages to our system. After then we need to create multiple worker which can consume our messages. And at least a small functional user interface in angular which uses the webapi. We will talk a lot of configurations, keeping secrets secret and other stuff which can make problems when connecting all those parts.

What we will not do!

This demo application/environment will be far away from a complete production ready application. There will be no authentication or other security things which are extremely important, nor sufficient error handling, unit tests or great design patterns inside each software piece, etc. The pattern here is more the overall environment with pipelines, message broker, small services, etc. The code logic will be very simple, so we can concentrate on things we want to learn here.

Which technologies/tools we will use for coding, deploying and hosting?

For programming the backend will use C#/.NET Core/WebAPI and Angular/TypeScript for the frontend. We use Azure DevOps for the build/release pipelines and source control (.git). The complete infrastructure will be created in Azure with Terraform for defining the infrastructure in code. In Azure we will use Event Hubs as our Message Broker, Azure Tables to store the Notifications, Application Insights as one of our notification receiver, Key Vault to keep our secrets secret, Container Registry for our Docker Images and a Kubernetes Sevice (AKS) for hosting and managing our Docker Container.

What kind of functionality are we developing?

I think of a very small “notifier” application could make sense here. I think with this, we get all parts explored. The functionality is very simple. The app provides an interface for creating, listing and resending notifications to there consumer.

I start explaining the flow at the top of the diagram below. First the user should be able to create a notification via the user interface (made here with angular). The ui calls the web api to create a notification. The web api stores the notification in the table and sends a notification message to the event hub. At least the two consumer (application insights worker and email worker) receive them and do there job. The web api provides an additional “get notifications” endpoint by which the ui can read them. So then the user could select one or the other and resend the notification(s).

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image by author

Actually we do not need this “complex building” to realize this simple functionality, but this one has the known advantages of a microservice architecture and scalable system which I will not explain here to keep this short as possible.

What are the next steps?

In each part I will explain one “brick” to get this all to work. I explain in every specific post what we do need and achieve here. In a real world project it would make more sense not to split all the infrastructure tasks in one part (and for example) the web api into another.

Before we are going to start we should prepare a little bit. So we need an Azure DevOps account. And create a project named “Notifier”. Make sure that you choose git for source control! The work item template does not matter to us, because we will not use it. Then we need an Azure account. When we have this done we can start. Following the steps. So then lets go … (But I will spare myself the saying “Let’s get your hands dirty.”)